Proteomic profile of differentially expressed proteins in the medial prefrontal cortex after repeated cocaine exposure.

Medial prefrontal cortex (mPFC) has been implicated in the reward process and the development of cocaine addiction. In the current study, we used a proteomics-based approach, combining two-dimensional gel electrophoresis (2-DE) with mass spectrometry (MS), to analyze protein expression profiles of rat mPFC after repeated cocaine exposure. Conditioned place preference (CPP) assay was used here to evaluate cocaine-induced reward effect in rats. We detected about 3100 protein spots in rat mPFC. After repeated cocaine exposure, 125 spots were changed by more than 1.1-fold of control levels. Among them, 71 spots with 1.5-fold or greater changes in protein expression over control levels have been identified, including 50 spots that were up-regulated and 21 spots that were down-regulated by repeated cocaine exposure. These identified proteins that showed significant changes in expression in mPFC after repeated cocaine exposure may be useful biomarkers for assessing cocaine abuse and potential new targets for investigating the mechanism of cocaine abuse.